Direct driving type optical fiber switch

ABSTRACT

A direct driving type optical switch is proposed. A row of V-grooves is formed on a base and a plurality of output optical fibers is arranged on one side of the base and respectively placed in the V-grooves. A movable input optical fiber is placed on another side of the base and atop a selected V-groove. The movable input optical fiber is pressed by a positioning block  446  and clamped tightly into the selected V-groove, whereby the input optical fiber is aligned with the output optical fiber in the selected V-groove for signal transmission.

FIELD OF THE INVENTION

[0001] The present invention relates to a direct driving type opticalfiber switch, especially to a direct driving type optical fiber switchusing V-groove to enhance alignment accuracy.

BACKGROUND OF THE INVENTION

[0002] There has always been a demand for increased capacity oftransmission for information. The lightwave communication system usingoptical fiber provides an ideal solution for mass data transmission.More particularly, the optical fiber has advantages of low losstransmission over long distance, high security, immunity to EMI, andlightweight. Therefore, the conventionally fancy technology such asfiber to the curb (FTTC) and fiber to the building (FTTB), even fiber tothe home (FTTH) and fiber to the desktop (FTTD) becomes mature andpopular. The optical fiber switch is an important component for buildingoptical network and therefore is under extensive research andimprovement.

[0003]FIGS. 1A and 1B show a prior art optical switch disclosed in U.S.Pat. No. 5,434,936. The prior art optical switch comprises a movableoptical fiber 101 with an end fixed to a tip of a cylindrical tube 103and with another end extruding into a cylindrical sleeve 106. Twomagnetic bodies 110 a and 110 b in a pipe shape arranged atop the inputoptical fiber 101. Solenoid coils 105 a and 105 b are provided so as tosurround the two magnetic bodies 110 a and 110 b. A pair of permanentmagnets 107 a and 107 b is located paralleled to the magnetic body 110 aand at equivalent intervals, and having the magnetic poles in theopposite direction. A pair of permanent magnets 107 c and 107 d islocated paralleled to the magnetic body 110 b and at equivalentintervals, and having the magnetic poles in the opposite direction.There are four fixed optical fibers 102 a, 102 b, 102 c and 102 d, oneof whose tips is opposite to a tip of the movable optical fiber 101, andwhich are fixed in a comer of a square hole within a columnar member 104fixed within the cylindrical sleeve 106. arranged atop the input opticalfiber 101. The magnetic fields of the solenoid coils 105 a and 105 b areattracted or repelled by those of the permanent magnets 107 a, 107 b,107 c and 107 d, thus moving the movable optical fiber 101 to a selectedcomer of the square hole within a columnar member 104.

[0004] However, in above-mentioned optical switch, the switch of themovable optical fiber is achieved by the composite action of thesolenoid coils and the permanent magnets. It is hard for the tip of themovable optical fiber to locate at a specific and accurate location.Therefore, considerable manual adjustment is required. The yield isreduced and the cost is increased.

[0005] Alternatively, the movable input optical fiber can be moved by astep motor. However, the positioning error for fiber alignment isrequired to be below ±0.5 μm. This imposes strict restriction for theaccuracy of the step motor. Moreover, the maintenance and purchase costsare increased.

SUMMARY OF THE INVENTION

[0006] It is the object of the present invention to provide a directdriving type optical fiber switch with simple structure and reducedcost.

[0007] In one aspect of the present invention, the optical fiber switchuses V-groove to enhance alignment accuracy and uses at least onepositioning block to clamp the movable input optical fiber into aselected V-groove.

[0008] In another aspect of the present invention, the optical fiberswitch uses V-groove and positioning block to reduce alignment error andenhance yield.

[0009] In still another aspect of the present invention, the opticalfiber switch uses V-groove and positioning block to reduce the accuracyrequirement for each device, thus decreasing cost.

[0010] The various objects and advantages of the present invention willbe more readily understood from the following detailed description whenread in conjunction with the appended drawing, in which:

BRIEF DESCRIPTION OF DRAWING

[0011]FIG. 1A shows a longitudinal sectional view of a prior art opticalswitch;

[0012]FIG. 1B shows a transverse sectional view of a prior art opticalswitch;

[0013]FIG. 2 shows a perspective view of an optical switch according toa preferred embodiment of the present invention;

[0014]FIG. 3 shows an exploded view of the optical switch in FIG. 2;

[0015]FIG. 4A is a sectional view of the optical switch in FIG. 2, whilethe input optical fiber is aligned to one of the output optical fibers;

[0016]FIG. 4B is another sectional view of the optical switch in FIG. 2,while the input optical fiber is aligned to the other output opticalfiber;

[0017]FIG. 5 shows an exploded view of an optical switch according toanother preferred embodiment of the present invention;

[0018]FIG. 6 shows an exploded view of an optical switch according tostill another preferred embodiment of the present invention;

[0019]FIG. 7A is a sectional view of the optical switch in FIG. 6, whilethe input optical fiber is raised above the V-grooves;

[0020]FIG. 7B is another sectional view of the optical switch in FIG. 6,while the input optical fiber is aligned to one of the output opticalfibers;

[0021]FIG. 8A shows an exploded view of an optical switch according tostill another preferred embodiment of the present invention;

[0022]FIG. 8B is a sectional view of the optical switch in FIG. 8A; and

[0023] Fig.9 shows an exploded view of an optical switch according tostill another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0024]FIGS. 2, 3 and 4A, 4B shows the perspective view, exploded viewand two sectional views of the present invention, respectively. Theoptical switch of the present invention comprises a base 22, anassembling stage 24, an input optical fiber 282 and two output opticalfibers 284 and 286 arranged in stacked fashion, a pressing block 226, apositioning stage 26 and two positioning blocks 262 and 264. The base 22has a V-groove 222 with a V-shaped cross section in a transversedirection. The input optical fiber 282 and the first output opticalfiber 284 are placed at two opposite sides of the V-groove 222 and analignment gap 288 is formed between the input optical fiber 282 and thefirst output optical fiber 284. A positioning hole 224 is formed on theV-groove 222 and vertically through the base 22. The positioning hole224 is near a coupling end of the input optical fiber 282. The pressingblock 226 is arranged atop the input optical fiber 282 to retain theinput optical fiber 282. The assembling stage 24 has a V-groove 242 onbottom thereof and used to accommodate the second output optical fiber286, whereby the two output optical fibers 284 and 286 are arranged instacked fashion when the assembling stage 24 is assembled with the base22. The assembling stage 24 also has a positioning hole 244 formed atopthe input optical fiber 282 and an eyehole 246 atop the alignment gap288 for observing alignment condition of fibers. The two positioningblocks 262 and 264 are engaged into the positioning holes 224 and 244,respectively, and abut to two inner walls of the positioning stage 26.

[0025] The positioning stage 26 is moved in up and down directions topush the two positioning blocks 262 and 264, respectively. As a result,the input optical fiber 282 is clamped to the V-groove 242 or theV-groove 222 by the positioning blocks 262 and 264 and is aligned to theoutput optical fiber 286 or the output optical fiber 284, respectively.

[0026]FIG. 5 shows an exploded view of another preferred embodiment ofthe present invention. The optical switch according to this embodimentcomprises a base 32, an input V-groove 322 on one end of the base 32,and two juxtaposed output V-grooves 323 and 324 on another end of thebase 32. A dent 326 is formed between the input V-groove 322 and theoutput V-grooves 323, 324. The dent 326 has two lateral sides beinglinear extension of each outer bevel of the output V-grooves 323, 324.The dent 326 has two positioning grooves 327 and 328 on two lateralsides thereof, respectively. A first output optical fiber 384 and asecond output optical fiber 386 are placed in the output V-grooves 323and 324, respectively, with their coupling tips slightly extruding intothe dent 326. An input optical fiber 382 is placed in the input V-groove322 with its coupling tip extruding into the dent 326 and placed inproximity of the coupling tips of the two output optical fibers 384 and386. Moreover, an alignment gap 388 is formed between the input opticalfiber 382 and the two output optical fibers 384 and 386.

[0027] The optical switch according to this embodiment further comprisesan assembling stage 34 atop the base 32. The assembling stage 34 has, onbottom thereof, an input V-groove (not shown), two output V-grooves 343and 344, a dent (not shown), a positioning groove 347 and anotherpositioning groove (not shown) with position corresponding to relevantparts of the base 32. Therefore, the assembling stage 34 and the base 32together clamp the input optical fiber 382 and the two output opticalfibers 384 and 386 in corresponding V-grooves, while the coupling tip ofthe input optical fiber 382 is movable in the dent 326. The assemblingstage 34 further has an eyehole 349 atop the alignment gap 388 toobserve alignment condition. The positioning grooves of the base 32 andthe assembling stage 34 form two positioning holes after assembling ofthe base 32 and the assembling stage 34. Two positioning blocks 362 and364 are engaged into the two positioning holes, respectively, and abutto two inner walls of a U-shaped positioning stage 36.

[0028] The positioning stage 36 is moved to push the two positioningblocks 362 and 364, respectively. As a result, the input optical fiber382 is moved to be clamped to one of the new lateral V-grooves formed bythe lateral sides of the dent 326 on the base and the lateral sides ofthe dent 326 on the assembling stage 34 after the assembling stage 34assembled to the base 32, whereby the input optical fiber 282 is alignedto the output optical fibers 384 or to the output optical fiber 386 forswitching optical signal.

[0029]FIGS. 6, 7A and 7B shows still another preferred embodiment of thepresent invention. The optical switch according to this embodimentcomprises a base 42, an assembling stage 44, an input stage 46 and apositioning block 446. A row of V-grooves 422 is formed on upper surfaceof the base 42 and adjacent to each other along a transverse direction.Each of the V-groove 422 accommodates an output optical fiber 484 on oneend thereof. The assembling stage 44 has a row of V-grooves 445 on onebottom side thereof and corresponding to the row of V-grooves 422 on thebase 42, and a dent 443 on another bottom side thereof. The dent 443 haslarger depth than that of the V-groove 445 and a width covering totalbreadth of the row of the V-grooves 445. The assembling stage 44 has apositioning hole 444 atop the dent 443 and vertically through theassembling stage 44. The output optical fibers 484 are clamped incorresponding V-grooves 422 and 445 when the base 42 is assembled withthe assembling stage 44.

[0030] The input stage 46 has a V-groove 462 for accommodating an inputoptical fiber 482 and a pressing block 464 is placed atop the inputoptical fiber 482 to enhance the positioning of the input optical fiber482. The input optical fiber 482 has a coupling tip inserting into thedent 443 and placed in proximity of the output optical fibers 484 withan alignment gap 488 formed. Moving the input stage 46 moves the inputoptical fiber 482 laterally atop the V-grooves 422 on the base 42.Therefore, the input optical fiber 482 is moved atop one desired outputoptical fiber 484 and then the positioning block 446 is inserted throughthe positioning hole 444 to clamp tightly the input optical fiber 482,whereby the input optical fiber 482 is aligned with the desired outputoptical fiber 484. The assembling stage 44 further has an eyehole 448atop the alignment gap 488 to observe alignment condition.

[0031] More particularly, in above preferred embodiment, a plurality ofoutput optical fibers 484 are respectively placed in a row of V-grooves422 on the base 42 and each occupies part of corresponding V-groove 422.The movable input optical fiber 482 is placed atop of another part ofthe V-groove 422. After the input optical fiber 482 is moved to aposition corresponding to desired output optical fiber 484, thepositioning block 446 is operated to clamp tightly the input opticalfiber 482 into the V-groove 422, whereby the input optical fiber 482 isaligned with the desired output optical fiber 484.

[0032] In general the input stage 46 is moved by a servomotor or a stepmotor. With the help of the positioning block 446, which clamps tightlythe input optical fiber 482 into the V-groove 422, the tolerance of theservomotor or a step motor is alleviated to ±20 μm instead of ±0.5 μm.Therefore, the manufacture cost and the maintenance cost are reduced.

[0033]FIGS. 8A and 8B shows still another preferred embodiment of thepresent invention. The optical switch according to this embodiment hassimilar components as those shown in FIG. 2. A positioning cylinder 86and two linking plates 867, 868 replace the U-shaped positioning stage26. By using the linking plates 867 and 868, the positioning cylinder 86and positioning blocks 864, 862 are linked together. The cylinder 86 andthe two linking plates 867, 868 have the advantages of easy manufacture.The positioning cylinder 86 is moved in up and down directions to drivethe input optical fiber 282 through the two linking plates 867, 868 andpositioning blocks 862, 864.

[0034] Moreover, as learned from experiment, the positioning blockpushing the input optical fiber 282 away from horizontal position (thepositioning block 862 in FIG. 8B) is preferably to have larger distanceto the alignment gap 288 in comparison with another positioning block(the positioning block 864 in FIG. 8B). Therefore, the positioning block864 has closer distance to the output optical fibers 286, 284, as beingcompared with the positioning block 862.

[0035]FIG. 9 shows an exploded view of still another preferredembodiment of the present invention. The optical switch according tothis embodiment comprises a base 92, an assembling stage 94, an inputoptical fiber 982, two output optical fibers 984, 986 and a positioningcylinder 96. The positioning cylinder 96 is in contact with a pressingtongue 946 and an armature 956 of a relay 95. The positioning cylinder96 is pushed by the pressing tongue 946 and the armature 956 of therelay 95 to move in up and down directions through a positioning hole944 of the assembling stage 94 and a positioning hole 924 of the base92. The armature 956 of the relay 95 pushes upward the positioningcylinder 96 to press against the pressing tongue 946 when one end of thearmature 956 is close to one distal end 952 of the relay 95. On thecontrary, the positioning cylinder 96 is not pushed by the armature 956and is pressed downward by the pressing tongue 946 when one end of thearmature 956 is close to one pressing end 954 of the relay 95.

[0036] The positioning cylinder 96 is provided with two positioningplates 967, 968, and is movable in a positioning groove 928 of the base92 and a positioning groove 942 of the assembling stage 94,respectively. The two positioning plates 967 and 968 are in contact withthe input optical fiber 982. So that when the positioning cylinder 96move up and down, the two positioning plates would be driven up and downto switch the input optical fiber 982 for aligning with one of theoutput optical fibers 984 and 986.

[0037] The assembling stage 94 preferably has a bevel surface tofacilitate the assembling with the base 92. The pressing tongue 946 canbe replaced by another relay. Moreover, if the pressing tongue 946 isfixed at other location than that shown in FIG. 9, an eyehole (notshown) can be provided on the assembling stage 94 for observing thealignment condition of the fiber. In above-mentioned preferredembodiments, the positioning stage or positioning cylinder can be movedby mechanical force. Alternatively, the positioning stage or positioningcylinder can be made of magnetic material and driven by electromagneticforce.

[0038] Although the present invention has been described with referenceto the preferred embodiment thereof, it will be understood that theinvention is not limited to the details thereof. Various substitutionsand modifications have suggested in the foregoing description, and otherwill occur to those of ordinary skill in the art. Therefore, all suchsubstitutions and modifications should be intended and be embracedwithin the scope of the invention as defined in the appended claims.

What is claimed is:
 1. An optical fiber switch, comprising: a basehaving a V-groove thereon and a positioning hole formed at apredetermined location on said V-groove and vertically through saidbase; an input optical fiber arranged in one side of said V-groove andatop said positioning hole, said input optical fiber having a movabletip; a first output optical fiber arranged in another side of saidV-groove and separated by an alignment gap with respect to said inputoptical fiber, said first output optical fiber being parallel to andleveled with said input optical fiber; an assembling stage arranged atopsaid base and having a V-groove on bottom thereof and corresponding tosaid V-groove of said base; a second output optical fiber arranged insaid V-groove of said assembling stage such that said second outputoptical fiber is stacked on said first output optical fiber when saidassembling stage is assembled with said base; and at least onepositioning block movably fit in said positioning hole, said positioningblock being driven to press against said tip of said input opticalfiber, whereby said input optical fiber is clamped to one of the bottomof said V-groove of said base and said V-groove of said assemblingstage, and be aligned to one of said said first output optical fiber andsaid second output optical fiber, respectively.
 2. The optical fiberswitch as in claim 1, further comprising a pressing block atop said baseand used to retain said input optical fiber.
 3. The optical fiber switchas in claim 1, further comprising an eyehole formed on said assemblingstage and atop said alignment gap, thus facilitating said observation offiber alignment.
 4. The optical fiber switch as in claim 1, furthercomprising a positioning hole formed on said assembling stage andcorresponding to said tip of said input optical fiber, anotherpositioning block being movably fit in said positioning hole of saidassembling stage, said positioning block in said assembling stage beingmoved with said positioning block in said base to ensure precisealignment of fibers.
 5. The optical fiber switch as in claim 4, furthercomprising a U shaped positioning stage with two inner walls on whichsaid positioning blocks in said assembling stage and said positioningblock in said base abut to ensure simultaneous movement of said twopositioning blocks.
 6. The optical fiber switch as in claim 5, whereinsaid positioning stage is driven by mechanical force.
 7. The opticalfiber switch as in claim 5, wherein said positioning stage is ofmagnetic material and driven by electromagnetic force.
 8. An opticalfiber switch comprising at least: a base having an input V-groove on oneend thereof, and two juxtaposed output V-grooves on another end thereof,a dent formed between said input V-groove and said output V-grooves,said dent having two lateral sides being linear extension of each outerbevel of said output V-grooves and having two positioning groovesvertically formed on two lateral sides thereof; an input optical fiberplaced in said input V-groove with its movable tip extruding into saiddent; a first output optical fiber and a second output optical fiber areplaced in said output V-grooves, respectively; an assembling stage atopsaid base and having, on bottom thereof, an input V-groove, two outputV-grooves, a dent, two positioning grooves with position correspondingto relevant parts of said base; said V-grooves of said base and saidassembling stage clamping said input optical fiber and said two outputoptical fibers therein when said base is assembled with said assemblingstage; said dent forming a space in which said tip of said input opticalfiber is movable; said lateral sides of said dent on said base and thelateral sides of said dent on said assembling stage form two new lateralV-grooves on both sides after said assembling stage assembled to saidbase; said positioning grooves of said base and said assembling stageforming two positioning holes after assembling of said base and saidassembling stage; and two positioning blocks slidably engaged into saidtwo positioning holes, respectively; said two positioning blockspressing said input optical fiber against the bottom of one of the newlateral V-grooves formed by said lateral sides of said dent on saidassembling stage and said lateral sides of said dent on said base,whereby said input optical fiber is aligned to one of said two outputoptical fibers.
 9. The optical fiber switch as in claim 8, furthercomprising an eyehole formed on said assembling stage and atop analignment gap between said input optical fiber and said output opticalfibers, thus facilitating said observation of fiber alignment.
 10. Theoptical fiber switch as in claim 8, further comprising a U shapedpositioning stage with two inner walls on which said positioning blocksin said assembling stage and said positioning block in said base abut toensure simultaneous movement of said two positioning blocks.
 11. Theoptical fiber switch as in claim 8, wherein said positioning stage isdriven by mechanical force.
 12. The optical fiber switch as in claim 8,wherein said positioning stage is of magnetic material and driven byelectromagnetic force.
 13. An optical fiber switch comprising at least:a base having a row of V-grooves on upper surface thereof and arrangedalong a transverse direction; a plurality of output optical fibers, eachof said output optical fibers accommodated in one end of correspondingV-groove; an assembling stage atop said base and having, on one bottomside thereof, a row of V-grooves corresponding to said V-grooves on saidbase; said V-grooves of said assembling stage assembled with saidV-grooves on said base to clamp said output optical fibers therein; saidassembling stage having, on another bottom side thereof, a dent withlarger depth than that of said V-groove and a width covering totalbreadth of said row of said V-grooves; said assembling stage having apositioning hole atop said dent and vertically through said assemblingstage; an input stage having a V-groove thereon; an input optical fiberaccommodated in said V-groove of said input stage and having a tipinserting into said dent, wherein said input optical fiber is movedlaterally atop said V-grooves on said base by moving said input stage; apositioning block slidable through said positioning hole and driven byan external force to clamp tightly said input optical fiber to saidbottom of one of said V-grooves of said base, whereby said input opticalfiber is aligned with corresponding output optical fiber.
 14. Theoptical fiber switch as in claim 13, wherein said input stage has apressing block placed atop said input optical fiber to enhance saidpositioning of said input optical fiber.
 15. The optical fiber switch asin claim 13, further comprising an eyehole formed on said assemblingstage and atop an alignment gap between said input optical fiber andsaid output optical fibers, thus facilitating said observation of fiberalignment.
 16. The optical fiber switch as in claim 13, wherein saidpositioning stage is driven by mechanical force.
 17. The optical fiberswitch as in claim 13, wherein said positioning stage is of magneticmaterial and driven by electromagnetic force.
 18. The optical fiberswitch as in claim 13, wherein said input stage is moved by one of aservomotor and a step motor.
 19. An optical fiber switch comprising atleast: a base having a V-groove thereon and a positioning hole formed ata predetermined location on said V-groove and vertically through saidbase; an input optical fiber arranged in one side of said V-groove andatop said positioning hole, said input optical fiber having a movabletip; a first output optical fiber arranged in another side of saidV-groove and separated by an alignment gap with respect to said inputoptical fiber, said first output optical fiber being parallel to andleveled with said input optical fiber; an assembling stage arranged atopsaid base and having a V-groove on bottom thereof and corresponding tosaid V-groove of said base; said V-groove of said assembling stagehaving a positioning hole formed at a predetermined location thereof; asecond output optical fiber arranged in said V-groove of said assemblingstage such that said second output optical fiber is stacked on saidfirst output optical fiber when said assembling stage is assembled withsaid base; and at least one positioning cylinder having two linkingplates extended from a top portion and a bottom portion thereof; saidtwo linking plates being connected to two positioning blocks movably fitin said positioning holes, said positioning block being driven to pressagainst said tip of said input optical fiber, whereby said input opticalfiber is clamped to one of the bottom of said V-groove of said base andsaid V-groove of said assembling stage and is opposite toone of saidfirst output optical fiber and said second output optical fiber,respectively.
 20. The optical fiber switch as in claim 19, furthercomprising an eyehole formed on said assembling stage and atop saidalignment gap, thus facilitating said observation of fiber alignment.21. The optical fiber switch as in claim 19, wherein said positioningblock pushing said input optical fiber away from horizontal position andsaid corresponding positioning hole have larger distance to saidalignment gap in comparison with another positioning block andcorresponding positioning hole.
 22. The optical fiber switch as in claim19, wherein said positioning cylinder is driven by an external forceattributed from one of a relay, a mechanical device, an electromagneticdevice and a combination thereof.
 23. An optical fiber switch comprisingat least: a base having a V-groove thereon and a positioning hole formedat a predetermined location on said V-groove and vertically through saidbase; an input optical fiber arranged in one side of said V-groove andatop said positioning hole, said input optical fiber having a movabletip; a first output optical fiber arranged in another side of saidV-groove and separated by an alignment gap with respect to said inputoptical fiber, said first output optical fiber being parallel to andleveled with said input optical fiber; an assembling stage arranged atopsaid base and having a V-groove on bottom thereof and corresponding tosaid V-groove of said base; said V-groove of said assembling stagehaving a positioning hole formed at a predetermined location thereof andconnected with said positioning hole of said base; a second outputoptical fiber arranged in said V-groove of said assembling stage suchthat said second output optical fiber is stacked on said first outputoptical fiber when said assembling stage is assembled with said base;and at least one positioning cylinder received in said positioning holeof said base and said positioning hole of said assembling stage; saidpositioning cylinder having two positioning plates; an external forcebeing operated on said positioning cylinder to move said positioningplates to press against said input optical fiber, whereby said inputoptical fiber is clamped to one of said bottom of said V-groove of andsaid base said V-groove of said assembling stage and is aligned to saidfirst output optical fiber said second output optical fiber,respectively.
 24. The optical fiber switch as in claim 23, wherein saidbase has a relay on bottom thereof and said relay having an armature toprovide said external force.
 25. The optical fiber switch as in claim24, wherein said positioning hole of said assembling stage passesthrough said assembling stage; and a pressing tongue is provided atopsaid assembling stage and can be pressed to be in contact with saidpositioning cylinder.
 26. The optical fiber switch as in claim 25,wherein said pressing tongue can be replaced by a relay.
 27. The opticalfiber switch as in claim 23, further comprising an eyehole formed onsaid assembling stage and atop an alignment gap between said inputoptical fiber and said output optical fibers, thus facilitating saidobservation of fiber alignment.
 28. The optical fiber switch as in claim23, wherein said positioning plate pushing said input optical fiber awayfrom horizontal position has larger distance to said alignment gap incomparison with another positioning plate.
 29. The optical fiber switchas in claim 23, wherein each of said base and said assembling stage hasa positioning groove corresponding to said position of said positioningplate, and said positioning plate is movable in correspondingpositioning groove.